Single chamber compressed air brake



Novl.`l7, 1931. w. HILDEBRAND v SINGLE CHAMBER COMPRESSED AIR BRAKEFiled Dec.

Patented Nov. 17 1931 UNITED ASTATES PATENT OFFICE WILHELM HILDEBRAND, FLICHTERFELDE, BERLIN, GERMANY SINGLE CHAMBER COMPBESSED AIB BRAKEApplication led December 6, 1929, Serial No. 412,174, and in Germany andAustria December 24, 1928.

This invention relates to single chamber structed in accordance with theinvention compressed air brakes for example of the 1s represented. kindin which a release valve is provided to L indicates the train pipe, Stthe control permit graduated release ofthe brake, which valve, n theilling groove, B the auxiliary f release valve is connected with theexhaust air reservoir which is divided by the par- 55 opening of thecontrol valve. tition Z into two spaces of which thesmaller Such devicesare known in which, besides is on the side towards the control valve St.the pressure of the brake cylinder, the train In the 'partition Z thereis a non-return valve pipe pressure and a constant pressure 1n a Ropening towardsthe smaller s pace. In 1 space filled through anon-return valve from addition, the partition Z is provided With 60 theauxiliarv air reservoir act on the release a choke bore D. V indicatesgenerally the apparatns,.and in which the auxiliary air releaseapparatus, which comprises the air reservoir is filled through the knownfilling release valve E provided with a spring e1 groove in the controlvalve when this is 1n and working in conjunction With a piston 5 therelease position. `With these known de.- cl which is bored through. Themovement e5 vices the release period mustbe so adjusted of this pistonis controlled by another pisby suitable dimensioning of the release boretion K which on one side is under the conin relation to the time whichis necessary fOr stant pressure of a chamber A filled from the fillingup of the auxiliary air reservoir, the reservoir B through a non-returnvalve that the auxiliary air reservoir is again coina1. and 0n the otherSide is under the mfp 0 pletely filled up, when the brake is releasedable pipe pressure'which influepces the pitsafter a full braking.Gtherwise when the ton K through a pipe Z1 connecting the train brake isexhausted and after release it is pipe L with the valve housing Thebrake immediately necessary to apply IC-be brak@ cylinder pressure tendsto move the bored pisy again, it may happen that the auxiliary restonllout 0f reach of the Valve E 75 ervoirs in the back part of the train arenot On braking, the Slide valves of the Contro] yet charged. or areincoinpletely charged, so valve St Opens the duct C leading to the brakethat with a fresh braking the necessary pres- Cylinder C, S0 that theauxiliary reservoir air sure is not at disposal. in order to displace@an HOW into the brake @Vlinder The comthe control valve into thebraking pOSitIOllmunication between the duct o1 and the air Aln the caseof long trains, such extended rerelease duct e2 is cut off bv the samemovelease periods have to be given that the workment of the slide.valve. n lconseouence of inc' 'of the brakes becomes difficult. d m llhe of he traii pirxie presuil, thepiston l coordine to the inventionthis i ou ty o ere easeva ve .un er e in u'ence is jiiveroome bvdividing the auxiliary air 0f the DTQSSUTQ H1 the Chamber A, mOVeS the8". reservoir into Atwo chambers, for example a bmedfllstol'l k1 RQMHSthe air release valve laraer and a smaller one` a non-return valve EWhldl; then cuzts Off the COIIITlUnlCatIfn bebeinfir provided betweenthese two chambers tweerlt e duct e and the Opemng oto t e at' l .0 andopeninglr towards the side of thesmaller mgwer for the purpose ofproducing a Chamb@ from Whlch wie the amlharv agr graduated release. thepressure in the train reservoinis filled through the control valve. pipeis only Slightlv increase the control A .mrtmon between tho tw? Clmmbprsm piston P in the control valve St is moved to which the non-returnvalve is located. may the left and the brake @Vlinder duct ci is =5 beprovided with a lchoke bore for the Filling placed in Connection withthe duct en; th@ of the larger chamber ot' the auxiliary air brake@Vlinder pressure Combined with the VQSQI'VOI'- increasedl train pipepressure displaces the In Figure l of the accompanying drawpistons k1and K t0 the right hand Side. By

ings, a diagrammatic example of the conthe movement ofthe piston k1 awayfrom the 100 struction of a single chamber brake conair release valve E,brake cylinder air is allowed to dow out through the bore in the saidpiston to the opening o to atmosphere, until in consequence of the fallof the brake cylinder pressure the piston K which is exposed to a higherpressure in the chamber A moves the piston k1 again to the left, whenthe bore in the piston /cl is again closed by the valve E. Owing' to thebore D in the partition Z being small, the pressure in the chamber ofthe reservoir situated to the right of the partition Z, rises morequickly than that in the other chamber of the auxiliary reservoir;therefore a renewed braking operation after the release can be rapidlyeffected without necessitating a considerable exhaustion of air from thetrain pipe. For the same reason, the preparation for renewed braking' isreestablished. even with a long goods train, in a comparatively shorttime.

'The arrangement can also be appropriatelv used with single chambercompressed air brakes having two control valves acting on the brake andrelease process. if with the control valve a subsidiary supply of thebrake cylinder, in the case of pressure losses, is effected.

This modification is illustrated in Figure 2, in which the valve E inthe casing Vacts as a, second control valve, and is adapted to beoperated by the valve @2, behind which is a connection f from the mainchamber B of the auxiliary reservoir. rThe brake cylinder is directlvconnected with the casina' V by the conduit e. The exhaust outlet o islocated in the casing St oit the first control valve` instead oit in thecasina V. and the conduit 01 connects the portion of the casinaI V whichis located in front of the piston k1 with the said outlet in the releaseposition. When the brake is applied. if the pressure in the brakecylinder falls owing to leakage at its piston, the pistons K and iclwill be actuated by the pressure in the chamber A to reopen the valve V2and admit a further supply of compressed air to the brake cylinderthrough the conduit ef.

lnstead of the hole D made in the partition, a pipe connection betweenthe train pipe and the larger chamber of the auxiliary air reservoir maybe provided-as shown in` Fie;- ure 3in which pine connection is locateda non-return valve R1 opening towards the reservoir, and a. throttle.

What l claim and desire to secure by Letters Patent of the United Statesis 1. In a compressed air brake. a train pipe. an auxiliary reservoir,`acontrol valve comprising a piston exposed on one side to the variablepressure in the train pipe. and on the other side to auxiliary reservoirpressure, said auxiliary air reservoir beine divided into two chambers.one of which chambers is in free communication with the adjacent sideor" said piston to actuate said piston against said train pipe pressureupon reduction ofthe latter pressure, and thereby upon said reduction toplace said chamber in communication with the brake cylinder, anon-return valve interposed between the said two chambers and adapted toopen towards the one of said chambers which is in free communicationwith the control valve piston to reinforce the pressure in the lastnamed chamber from the contents of the other of said chambers, and meansfor re-chargiug said other chamber.

2. In a compressed air brake, a train pipe, an auxiliary reservoir, acontrol valve comprising a piston exposed on one side to the variablepressure in the train pipe, and on the other side to auxiliary reservoirpressure, said auxiliary air reservoir being divided into two chambers,one of which' chambers is in free communication with the adjacent sideof said piston to actuate said piston against said train pipe pressureupon reduction of the latter pressure, and thereby upon said reductionto place said chamber in communiy cation with the brake cylinder, anon-return valve interposed between the said two chambers and adapted toopen towards the one of said chambers which is in free communicationwith the control valve piston to reinforce the pressure in the lastnamed chamber from the contents of the other of said chambers, means forre-charging said other chamber,

and a release valve adapted to cooperate with said control valve tocontrol the graduated exhaust of air from the brak'e cylinder, saidrelease valve also being adapted to cooperate in the filling of thebrake cylinder.

3. ln a compressed air brake, a train pipe, an auxiliary reservoir, acontrol valve comprising a piston exposed on one side to the variablepressure in the train pipe, and on the other side to auxiliary reservoirpressure, said auxiliary reservoir being divided into two chambers ofunequal size, the smaller of said chambers being in free communicationwith the adjacent side of said piston to actuate said piston againstsaid train pipe pressure upon reduction of the latter pressure andthereby upon said reduction to place said smaller chamber incommunication with the brake cylinder, a non-return valve interposedbetween the said two chambers and adapted to open towards the smallerchamber to reinforce the pressure in the latter from the contents of thelarger chamber, and means for re-charging said larger chamber.

4. In a compressed air brake, a train pipe, an auxiliary reservoir, acontrol valve comprisina` a piston exposed on one side to the variablepressure in the train pipe and on the other side to auxiliary reservoirpressure, a partition dividing said auxiliary reservoir into an activechamber and a reserve chamber, said active chamber being in freecommunication with the adjacent side of said piston to actuate saidpiston against said train pipe pressure upon reduction of the latinto anactive chamber and a reserve chamter pressure, a non-return valve insaid partition adapted to open to allow passage of air to the activechamber from the reserve chamber to reinforce the pressure actingagainst the train pipe pressure, and means for recharging the reservechamber.

5. In a compressed air brake, a train pipe, a control valve having afilling groove, an auxiliary reservoir, a partition dividing saidreservoir into two chambers of unequal size, the smaller of saidchambers being in free communication with said control valve to actuatethe same against the train pipe pressure on reduction of the latterpressure, and a non-return valve in said partition adapted to open togive passage to air from the larger of said chambers to said smallerchamber, said partition having an aperture to eect filling of saidlarger chamber from the train pipe through said filling groove and saidaperture upon restoration of normal pressure in the train pipe.

6. In a compressed air brake. a train pipe, an auxiliary reservoir, acontrol valve comprising a piston exposed on one side to the variablepressure in the train pipe and on the other side to auxiliary reservoirpressure, a partition dividing said auxiliary reservoir ber, said activechamber being in free communication with the adjacent side of saidpiston to actuate said piston against said train pipe pressure uponreduction of the latter pressure, a non-return valve in said partitionadapted to give passage to air from said reserve chamber to said activechamber to reinforce the pressure in said active chamber uponapplication of the brake, and a connection controlled by another;vnon-return valve betweemsaid train pipe and said reserve chamber toeffect re-charging of said reserve chamber. v

WILHELM HILDEBRAND.

